Flink elasticsearch sink代码示例

下面是一个基于 Flink 的 Elasticsearch Sink 的代码示例：

import org.apache.flink.api.common.functions.RuntimeContext;
import org.apache.flink.streaming.api.functions.sink.RichSinkFunction;
import org.apache.flink.streaming.connectors.elasticsearch.ElasticsearchSinkFunction;
import org.apache.flink.streaming.connectors.elasticsearch6.ElasticsearchSink;
import org.apache.flink.streaming.connectors.elasticsearch6.RestClientFactory;
import org.apache.flink.streaming.connectors.elasticsearch6.RestClientFactoryImpl;
import org.apache.flink.streaming.connectors.elasticsearch6.index.IndexRequestBuilder;
import org.apache.flink.util.Preconditions;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.Requests;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;

import java.util.HashMap;
import java.util.Map;

public class FlinkElasticsearchSinkExample {

    public static void main(String[] args) {

        // set up Flink environment

        // set up Elasticsearch sink configuration
        Map<String, String> config = new HashMap<>();
        config.put("cluster.name", "elasticsearch");
        config.put("bulk.flush.max.actions", "1");

        // create Elasticsearch sink
        ElasticsearchSink.Builder<ElasticsearchMessage> esSinkBuilder = new ElasticsearchSink.Builder<>(
                config,
                new ElasticsearchSinkFunction<ElasticsearchMessage>() {
                    public IndexRequest createIndexRequest(ElasticsearchMessage element) {
                        try {
                            XContentBuilder builder = XContentFactory.jsonBuilder();
                            builder.startObject();
                            {
                                builder.field("timestamp", element.getTimestamp());
                                builder.field("message", element.getMessage());
                            }
                            builder.endObject();
                            return Requests.indexRequest()
                                    .index("flink-elasticsearch-sink")
                                    .type("_doc")
                                    .id(element.getId())
                                    .source(builder);
                        } catch (Exception e) {
                            throw new RuntimeException(e);
                        }
                    }

                    @Override
                    public void process(ElasticsearchMessage element, RuntimeContext ctx, RequestIndexer indexer) {
                        indexer.add(createIndexRequest(element));
                    }
                });

        // create and add RestClientFactory
        esSinkBuilder.setRestClientFactory(new RestClientFactoryImpl());

        // add Elasticsearch sink to Flink job
        env.addSource(new FlinkKafkaConsumer<>("my-topic", new SimpleStringSchema(), properties))
                .map(new MyMapFunction())
                .addSink(esSinkBuilder.build());
    }

    // POJO representing Elasticsearch message
    public static class ElasticsearchMessage {
        private String id;
        private long timestamp;
        private String message;

        public ElasticsearchMessage(String id, long timestamp, String message) {
            this.id = id;
            this.timestamp = timestamp;
            this.message = message;
        }

        public String getId() {
            return id;
        }

        public void setId(String id) {
            this.id = id;
        }

        public long getTimestamp() {
            return timestamp;
        }

        public void setTimestamp(long timestamp) {
            this.timestamp = timestamp;
        }

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }
    }

    // custom implementation of RestClientFactory
    public static class RestClientFactoryImpl implements RestClientFactory {
        @Override
        public void configureRestClientBuilder(org.elasticsearch.client.RestClientBuilder restClientBuilder) {
            // set up authentication if needed
        }
    }

}

注意：在 `configureRestClientBuilder` 方法中可以设置 Elasticsearch 的认证信息。